Throw error when a word for cross compile doesn't have assembly.

Author: Molorius

pkg/forth/word.go

@@ -220,6 +220,9 @@ func (w *WordPrimitive) BuildAssembly(u *Ulp) (string, error) {
 	asm := make([]string, 0)
 	switch u.compileTarget {
 	case UlpCompileTargetToken:
+		if len(w.Ulp.Asm) == 0 {
+			return "", EntryError(w.Entry, "does not have any subroutine threaded assembly")
+		}
 		asm = append(asm, w.Ulp.Asm...)
 		switch w.Ulp.Next {
 		case TokenNextNonstandard:
@@ -233,6 +236,9 @@ func (w *WordPrimitive) BuildAssembly(u *Ulp) (string, error) {
 			return "", fmt.Errorf("Unknown compile target %d, please file a bug report", w.Ulp.Next)
 		}
 	case UlpCompileTargetSubroutine:
+		if len(w.UlpSrt.Asm) == 0 {
+			return "", EntryError(w.Entry, "does not have any subroutine threaded assembly")
+		}
 		asm = append(asm, w.UlpSrt.Asm...)
 		if !w.UlpSrt.NonStandardNext {
 			standardNext := []string{

util/pulse_test.f

@@ -17,10 +17,13 @@
 
 \ create the assembly to toggle a pin as fast as possible
 string" reg_wr 257, 28, 28, 1\nreg_wr 258, 28, 28, 1\n"
-string" unique_label_to_skip_assembly_optimizations_in_pulse_test_f:\n"
-string" jump __next_skip_load"
-3 \ 3 assembly objects to compile
-assembly asm-pulse \ create the assembly word named "asm-pulse"
+string" __safe_jump:\n"
+2 \ number of assembly objects to compile
+string" reg_wr 257, 28, 28, 1\nreg_wr 258, 28, 28, 1\n"
+string" __safe_jump:\n"
+2 \ number of assembly objects to compile
+assembly-both asm-pulse
+token_next_skip_load last set-ulp-asm-next
 
 : main
     pin_init